1. The Field of the Invention
The present invention relates to electronic controllers for externally powered prosthetic limbs. More particularly, the present invention relates to an electronic controller which operates a tactile force feedback system for presenting electronic sensory information to a human user's intact tactile sense and which provides self-calibration means for adjusting selected user-dependent operating parameters to various environments and conditions.
2. The Relevant Technology
Prosthetic limbs are well known and utilized by thousands of amputees. Preferably, a prosthetic limb is durable and lightweight, requires little or no maintenance, and includes suitable mechanical drive units, e.g., motors, for effecting desired movements and functions, and a power source for the drive units, such as a battery or batteries. In addition, a prosthetic limb is preferably aesthetically pleasing in that its size and shape is similar to the natural limb being replaced. Within these constraints, a prosthetic limb should also have the capability to perform various useful functions of the missing limb efficiently and in a smooth and consistent manner. Although reproducibility of the performance, at will, of all human limb function and motions has remained an elusive goal, many advancements have been made in prosthesis technology.
Prosthetic devices are preferably controlled through self-contained electronic controller means such as a microprocessor or dedicated circuitry. Sophisticated controllers comprising multiple input acceptance means for permitting the processing of input commands from various sources including myoelectric inputs, potentiometer inputs, accelerometer inputs, touch inputs, and electronic sensory inputs such as force, pressure, or temperature sensor inputs, are known in the art. Controllers comprising multiple output deliverance means for permitting either output proportional to input, i.e., open loop operation, or output proportional to the difference between the actual result and a desired result, i.e., closed loop operation are also known in the art. Additional features, such as a power-saving mode for shutting down or cutting back the power to the motor under certain conditions, may also be advantageously incorporated into the controller.